Question

A car has a kinetic energy of 2000 J. What will be its kinetic energy if its speed is doubled?

Answer 1

If speed is increases, the kinetic energy is also increases because kinetic energy and velocity are directly proportional.

The Kinetic energy is 8000J

KE = 2000 J

mv²/2 = 2000 J

When speed gets doubled.,

= m(2v)²/2

= 4mv²/2

= 4 * (mv²/2)

= 4 * 2000 J

= 8000 J

Answer 2

Explanation:

SOLUTION

Let m and v be the mass and speed of the car respectively

=> K.E. = 1/2 mv²

=> 2000 = 1/2 mv²

If v becomes 2 v, then K.E. = 1/2 * m * (2 v)² = 1/2 * 4 * mv² = 4 * 2000 = 8000 J